Valve device for absorption of the gas components

ABSTRACT

A valve device having a filter with at least a lower and upper compartment. The lower compartment is in fluid communication with a collection bag via apertures. The lower compartment is defined by a first division plate and a bottom wall. This lower compartment is filled with an odor absorbing substrate. One embodiment includes two lower compartments wherein the gas entering the lower compartment from the collection bag through the apertures, circulates along the length of the compartment, around the lower division plate, and along the length of the compartment toward the opening.

FIELD OF THE INVENTION

This invention concerns a valve device or filter house which can beused, for example, in stoma bags, especially ileostomy bags, which inone embodiment have an extended gas transport path, and which areself-closing when the moisture in the filter exceeds a certain limit.

BACKGROUND OF THE INVENTION

Surgical procedures such as colostomy, ileostomy and urostomy, where apermanent opening is created between the body's internal cavity and theenvironment, apart from the natural orifices, makes it necessary for thepatient to permanently wear a bag for the collection of bodily fluid,possibly faeces and faecal particles. This is necessary because thebody's natural orifices have shut-off musculature, such as sphinctermusculature, which is subject to voluntary control, while a surgicalstoma will directly discharge bowel contents/urine without the personhaving very much control over the process. The composition of thedischarges in the case of bowel stomata will be dependent on at whichpoint in the intestine the operation was performed, so that, e.g., inthe case of a colostomy the discharge will be of a thicker, almostnormal consistency, since a part of the water reabsorption capacity willbe intact, while in the case of ileostomy the discharge will includeparticles of different sizes in a thin liquid. In both cases intestinalgas, which is formed continuously in amounts from 50-1200 ml per day,measured as the amount which passes through the anus, will be passed outinto the bag together with the bowel contents. Thus in the case ofstomata, a considerable amount of gas could be passed out into the bagevery day.

Intestinal gas or flatus (intestinal gas which emerges through the anus)contains nitrogen, carbon dioxide, hydrogen, methane and trace elementsin varying amounts. Compositions have been measured (Kodama and Miura,J. Japan. Soc. Nutr. 2:149-152, 1949) such as 13-34% CO₂, 19-26% CH₄,20-27% H₂, 17-48% N₂ and less than 1% of indole, skatol, volatile aminesand hydrogen sulphide. The latter constitute the malodorous substancesin flatus and it is claimed that H₂ S can be detected by the sense ofsmell in as low a concentration as one part H₂ S in 100 million (0.01dpm). Thus a bad small can constitute a substantial disadvantage whenwearing a stoma bag.

Since substantial amounts of malodorous intestinal gas can thus beproduced and passed out into a stoma bag, this bag would rapidly becomeinflated if it was not provided with an outlet valve, and due to thesmell this valve also requires a filter which removes odour byabsorption, as it contains a deodorant material. A filter of this kindhas to provide a sufficient contact area between the odour-absorbingmaterial and the gas for adequate absorption of the odour, and thefilter must be able to prevent or reduce the formation of moisture inthe filter because a moist filter does not absorb gas. In the base ofileostomies, the build-up of moisture in the filter constitutes aparticularly serious problem compared with colostomy, since thedischarge is mainly liquid. Thus during the night it is difficult toavoid exposing the filter to liquid.

Attempts have been made to solve these problems in a number of patents,such as NO-PS 139029, 154904, 161293, SE-PS 454239 and DE-PS 3036009.

The prior art comprises the use of active carbon in the filter devicewith various designs for extending the gas flow path in the filter, suchas the case in which the valve device constitutes a plug where the gascirculates in winding channels formed in the actual filter or where thevalve device has standing walls which force the gas to circulate on aplane parallel to the valve device's outer top, which is parallel to thebag's surface and thereby increases the gas flow path approximately fivetimes (NO-PS 139029), or where the filter is oblong with an inletopening for gas and an outlet opening near each end (NO-PS 161293) orwhere the filter is composed of a gas channel round the periphery of therelated stoma bag (NO-PS 154904). The most common filter available onthe market, which is based on SE-PS 454239, permits the gas to flowthrough the thickness of the filter and includes no other modificationfor extending the gas flow path through the filter than that the gasenters the centre of the filter, through an opening which issubstantially smaller than the radius of the filter and smaller than thegas outlet opening from the filter, the transport path thus passingobliquely through the filter and thereby being extended. A filter ofthis kind can, e.g., be 20 mm in diameter, with a thickness of 2 mm andthe transport path will be approximately 10 mm.

Further factors which reduce the capacity of the filter are theproduction of channels in the filter mass, during which process theactive carbon is removed from the walls or show lacking cohesion in themiddle of the filter mass and falls apart. The gas will follow the pathof least resistance and will not be forced to circulate the whole filtermass, and the absorption capacity is reduced.

This problem is tried solved in DK-B2-147 293, in which the diffusionpath for the gases is no longer than from the periphery ofthe filter tothe centre. However, the filter material consists of a special cottonmatrix in which a great amount of fine granulated active carbon isembedded, enveloped by a gas-proof plastic dispersion. This gives a goodcohesion in the finely granulated carbon, and the plastic dispersionpenetrates the filter mass on several places and anchor the two layersto each other. Consequently the filter mass does not loosen from thewalls, and the particles will not fall apart. The gas is thereby forcedthrough the whole of the gas-absorbing mass.

A common problem for all filters included in the prior art is, however,as mentioned above, that when the filter becomes moist the filter mass'sodour absorption is reduced or ceases, thus allowing malodorousintestinal gas to be released into the environment. This is a seriousproblem for patients who are obliged to wear a stoma bag permanently.

Attempts have been made to solve this problem in the prior art byplacing a barrier layer of gas-permeable but moisture-impermeablematerial on the gas inlet side of the filter (NO-PS 161293, NO-PS139029, DE-PS 3036009). However, this or these hydrophobic layers cancause a blockage problem, the passage of gas in the moisture-inhibitinglayer being reduced or obstructed when particles and more solid contentsof the bowel discharge cover the filter surface and reduce thethrough-flow of gas. Especially in connection with ileostomi the contentof solid particles is considerable.

EP-A-0 235 928 comprises a deodorizing filter for ostomy equipment,where a filter body of a thickness of 0,25-3,0 mm is encased in ahousing of a flexible plastic sheet material. The inlet opening and theoutlet opening of the filter are located at the maximum distance fromeach other, at least 10 mm, preferably 30 mm. In preferred embodimentsof the filter, particularly suitable for ileostomi, the filter housingis provided on the side thereof facing the source of the intestinal gaswith a covering sheet with openings for the passage of incomingintestinal gas and/or with a layer of liquid-absorbing material.

SUMMARY OF THE INVENTION

In this filter a liquid-absorbing material is located upstream of thefilter body, in such a way that the absorbent material does not coverthe inlet opening for intestinal gas to be deodorized. Thus thisinvention cannot prevent liquid from entering the filter body when theabsorbing capacity of the material is exhausted, which would prevent thedeodorizing action of the filter body and produce unpleasant odour.

Thus it is the object of the present invention to provide pouch with avalve device with filter which gives a larger effective exposure surfacebetween the gas and the gas component absorbing material than filterswhich are included in the prior art, is especially suitable for, forexample ileostomies, in that the gas flow is stopped by the channelbeing closed when the filter becomes moist and inflation of the bagsignals that the filter/bag must be changed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is top plan view of valve device according to the presentinvention;

FIG. 1b is a cross-sectional view taken along lines 3--3' of FIG. 1.

FIG. 1c is a bottom plan view thereof;

FIG. 2a-2b are cross-sectional views taken along line 20--20' of FIG. 1.

FIGS. 3a to 3c are cross-sectional views of a test apparatus;

FIG. 4a is a cross-sectional view of a valve device according to asecond embodiment of the present invention; and

FIG. 4b is another cross-sectional view thereof.

The present invention comprises a valve device 1 which can be attachedto a valve opening 2 in, e.g., a stoma bag by means of a knownreversible, rapid lock technique or can be permanently welded to the bagor be an integrated part of the bag in that the wall of the bag servesas one of the valve walls. The valve device is round or oblong, with orwithout rounded ends viewed in a plane parallel to the wall 14 of thebag, and consists of a number of compartments, for example threecompartments, 5, 6 and 7, defined by the device's bottom 9, lowerdivision plate 10, upper division plate 11 and top 12, all with openings4, 15, 16 and 8 for gas through-flow, where the two lowest compartments5 and 6 are filled with an odour-absorbing means, and the uppercompartment is filled with a means which expands when it becomes moist.In a second design the valve device consists of two compartments 24, 25with inlet openings 26 and outlet openings 27 localized in the peripheryof the valve and opening 29 in the centre of the intermediate wall 23.The lower compartment 24, the gas absorption compartment, is filled withgas-absorbing means and the upper compartment, the expansioncompartment, is filled with a means which expands when moist. This meanscan be in powder form or in the form of a body.

The different versions of the invention will now be described in detailwith reference to the figures, where

FIG. 1 illustrates (a) the valve device viewed from the outlet side, (b)a cross section along the valve device's longest axis (line 3--3' inFIG. 1a) and (c) the valve device viewed from the gas inlet side;

FIG. 2 illustrates a section of the valve device through line 20--20' inFIG. 1 and demonstrates the possibilities for attaching the device to astoma bag, either a reversible rapid lock (a) or permanently welded intothe stoma bag (b);

FIGS. 3a, b, and c illustrates a test apparatus for testing an expandingsubstance's ability to stop the through-flow of gas under the influenceof moisture. A is active carbon, B is the expanding substance duringtesting and C is a partition of gas. Panel b shows the filter cylinderwith attached balloon, filled with air and water, and

FIGS. 4a and b illustrate a second design of the invention with twocompartments and granulated active carbon-impregnated foam as gasabsorption means.

FIG. 1 illustrates a version of the valve device according to thepresent invention, consisting of three adjacent compartments 5, 6 and 7,where the gas enters the valve device through a perforated opening 4 onthe end of the device in the bottom 9, circulates from compartment 5 tocompartment 6 through an opening 15 in the lower division plate 10 atthe valve device's opposite end, circulates back and into compartment 7through an opening 16, located in the upper division plate 11 at thefirst end, immediately above the gas inlet 4, and the gas flows on intothe compartment 7 towards the valve device's other end and leaves thevalve device through gas outlet 8, located near the other end. In around arrangement of the valve device the openings are located withmutual maximum distance between each opening. A flange 17 round thevalve device is designed with a turned down outer part, provided with aprojection 18 pointing towards the valve device and thus coming intoengagement with a projection directed from the valve device aperture ona collar round the stoma bag opening (FIG. 3a). This attachingmechanism, which is reversible, can be found, e.g., on stoma bagsproduced by ConvaTec and is known in the prior art. In another versionthe valve device is equipped with a single flange around the peripherywhich is used when the valve device is permanently welded to the bag bymeans of the prior art (FIG. 3c).

The valve device is made of a suitable material which does not reactchemically with the filter contents. In a preferred embodiment thedevice is made of a suitable plastic material.

The lower division plate 10 which separates compartments 5 and 6 isparallel to the bottom 9 and upper division plate 11 and located in sucha manner that the heights in compartments 5 and 6 are the same. Opening15 is located at the other end, opposite the gas inlet 4. Opening 16 islocated at the first end opposite opening 15 and this gives asubstantially extended diffusion path while at the same time the gascomes into contact with the odour-absorbing means over the entire widthof the valve device. This constitutes a profoundly enlarged contactsurface compensating for possible creation of channels in theodour-absorbing mass, with a considerably larger surface than that towhich the gases are exposed in, e.g., NO-PS 139029, where the gascirculates in channels formed in the odour-absorbing medium or inchannels formed in perpendicular walls in the filter device. Theodour-absorbing means can comprise active carbon, another deodorantmeans or a means which itself has a smell or a mixture of these means.

In the upper compartment 7, defined by the upper division plate 11 andthe top 12, there is filled a medium which is porous and gas permeablewhen dry, but which swells under the influence of moisture and closesthe gas outlet. Suitable means can include powderous plaster, sand or aa powder mixture of plaster and sand in suitable proportions in theregion of 30:70 to 70:30 (plaster:sand), preferably 50:50, dried andcompressed synthetic sponge material or superabsorbent such as soldcommercially as SUPERABSORBENS, LIC™, or any porous medium which swellswhen damp. Since compartment 7 is limited by relatively rigid walls, 11,12, the swelling will cause the gas flow to stop and no gas will bereleased from the bag even though the swelling stops the gas outletthrough the porous medium without this being enveloped by rigid walls.The bag will then swell and this is a signal that the filter has to bechanged. The valve device 1 with two filter layers and moisture-swellingmass is manufactured as a unit, replaced by a new one when the gasoutlet is clogged, and discarded.

FIGS. 4a and b illustrate a second design of the valve device accordingto the invention. This design has a division plate 23 and is separatedin a lower 24 and an upper 25 compartment. The outer walls of the valvedevice have a number of inlet openings 26 for gas in the wall 21 towardsthe interior of the stomi bag and a number of outlet openings 27 for gasin the wall 22 facing the ambience, where both sets of openings 26, 27are located in the periphery of the valve device and such that the setof openings 26 leads the gas into the lower compartment 24 and the setof openings 27 leads the gas out of the upper compartment 25. Thedivision plate 23 separating the two compartments 24 and 25 have anopening in the centre.

The walls 21, 22 and the division plate 23 are produced in any suitablematerial, for example plastic material which is gas-proof andmoisture-proof. In the periphery of the valve device the upper wall 22,the lower wall 24 and the division plate 23 are melted together to forma flange surrounding the whole valve device (FIG. 4b). This flange canbe heat sealed in a suitable opening in the stoma bag. In a seconddesign (FIG. 4a) the valve device is produced as an integrated part ofthe stoma bag such that the outer wall of the bag constitutes thedivision plate 23 and the valve device walls 21 and 22 are attached onthe inside and outside, respectively, of the bag by a gas-proof sealing.In both designs the valve design is permanently attached to the stomabag.

The lower compartment 24 is filled with a gas-absorbing substrate in aform which prevents creation of channels, for example granulated activecarbon impregated in a synthetic foam. In this foam impregnated withgranulated active carbon, the carbon is attached so firmly to the porewalls that the particles do not loosen. Hence the gas will be exposed tothe absorption capacity ofthe whole filter mass and the previouslymentioned creation of channels is avoided.

The upper compartment 25 is filled with a material which swells orexpands when moist and closes the gas outlet. Suitable means arementioned previously.

The odorous, moist intestinal gas enters the valve device through theopenings 26, passes through the odour-absorbing material which will notbe canalized in the lower compartment 24, through openings 29, into theupper compartment 25 and leaves through the openings 27. Deposition ofmoisture in the filter material, which in the lower compartment willlead to a reduction of the odour absorption, according to the presentinvention will lead to swelling of the substrate in the uppercompartment and closure of the gas outlet. Exposure of moisture in theform af a direct contact between the valve device and liquid in thestoma bag will produce the same effect. The stoma bag will inflate as asignal to change the valve device/bag. Even through the gas pressure inthe bag increases with t accumulation of gas the closed filter remainsgas-proof.

The present design of the valve device is not limited to any specificshape, a the number of division plates in the valve device can beincreased such that there are several separated layers withgas-absorbing substrate, while at least one upper compartment alwayswill contain a moisture expanding substrate.

In the following the invention will be further described and illustratedby examples.

EXAMPLE 1 A Test Apparatus for Testing the Filter Mass in the ValveDevice

The test apparatus is illustrated in FIGS. 3a, b, and c and consists ofa plastic cylinder, corked at both ends by perforated corks, where thedownstream hole has a smaller diameter than the upstream hole. Thecylinder is filled with, e.g., active carbon A, and the expandingsubstance B, during testing. Between the two layers there is a partitionof gas C. To this filter cylinder there is fitted a bag of elastic,airtight material such as a balloon, which is filled approximately 1/4full of water and 3/4 full of gas or air. When the test apparatus is putinto operation, supported in such a manner that the filter cylinder isvertical and points upwards, the air/gas will leak out through thefilter cylinder, the balloon will collapse and the filter cylinder willcome into contact with water. The moisture will be drawn up through thefilter and reach the test substance B.

By compressing the balloon it can be checked whether the filter cylinderhas become blocked. This test apparatus simulates the situation in whicha valve device according to the present invention is inserted in a stomabag.

EXAMPLE 2 The Testing of Different Materials Which Expand Under theInfluence of Moisture

The filter cylinder was filled with active carbon as test substance Aand as test substance B there was used 1) a mixture of plaster and sand(50:50, plaster/sand), 2) dried synthetic sponge material, and 3)Superabsorbens, LIC™. The balloon was filled with air and water asdescribed in example 1.

In all three cases the through-flow of air was stopped when the moisturereached the test substance B in the filter cylinder.

In all three cases the balloon was thereafter disconnected and theimpermeability of the filter cylinder to the through-flow of gas wastested with air under a pressure of 6 bar. The filter cylinder did notallow air to pass through in any of the three cases.

EXAMPLE 3 Testing of the Second Valve Device Design According to theInvention with Ileostomi Bag

The example shows a testing of ileostomi bags with the second design ofthe valve device according to the invention, in which the lowercompartment 24 is filled with a synthetic foam impregnated withgranulated active carbon, and the upper compartment 25 is filled withSuperabsorbens, LIC™. The test continues over six days, and in thebeginning of the period intake of food and liquid which is known toproduce air in the gastrointestinal tract was emphasized. This intake isspecified by time of the meal and the type of food consumed. No specificindication of time of meal and type of food means that normal mealrythm, comprising three bread meals and one dinner a day, was followed.

Day 1

5 p.m. A meal comprising salmon, shrimps, beer and champagne wasconsumed.

6 p.m. Bag 1 was attached.

9-11 p.m. Big meat supper with wine, beer and brandy.

1.30 a.m. Went to bed. The filter functioned all the time adequatelywithout creation of odour.

Day 2

6.30 a.m. Awakening. The filter iss closed and the bag is slightlyinflated by gas. The typical balloon shape which is common to ileostomicbags without valve device was not observed. Bag 1 was used all throughthe day.

8-9 p.m. Fish dinner with a lot of beer. Continued to use bag 1 in orderto test whether an increased gas pressure in the stomic bag should openup the valve device. No reopening nor any smell was observed.

1.30 a.m. Bag 1, which was used for 31,5 hours, was disconnected. Bag 2was connected.

Day 3

7 a.m. Awakening. The bag was slightly inflated, but the valve devicewas open. No odour was observed.

3 p.m. The valve device was completely closed.

23.30 p.m. The valve device was still closed. No odour was observed, andthe bag worked like a common ileostomic bag without the valve device.Bag 2 was disconnected. Bag 2 was used for 34 hours. Bag 3 wasconnected.

Day 4

The valve device in bag 3 was closed during the night. Even though thebag showed no typical balloon-shape, which would have been the case ofileostomic bags without valve device, no odour or leak from the valvedevice was observed. Bag 3 was used all through the day and thefollowing night.

Day 5

9 a.m. Bag 3 was disconnected after 33,5 hours' use. No balloon-shape,no leak, no odour was observed. Bag 4 was connected. The filter in thisbag remained open and functioned all through the day. No smell wasobserved.

6 p.m. The valve device closed. The same bag was used all through thenight.

Day 6

7 a.m. Awakening. No odour was observed, nor any leak, but the bag wasnow shaped like a balloon. Bag 4 was disconnected after 22 hours of use.

General Conclusion

The valve device according to the invention was tested in one subjectduring a period of 6 days, comprising a common Norwegian regime of mealsin addition to some larger intake of air producing food at abnormaltimes of the day. The valve device worked adequately in this period, andif the bag is changed twice during 24 hours, all problems with air inthe bag will be eliminated. It is especially promising that if a new bagwith a valve device according to the invention is connected just beforegoing to bed, it will last all through the night. This is a period whenileostomic bags will normally be exposed to the liquid content of thebag. Generally the valve device seems to be open longer in the day timewhen the subject is in a upright position, because the filter mass inthis position will not easily be in contact with the liquid in the bag.When the valve device was taken apart, it was observed that only about25% of the Superabsorbens was moist when the valve device was closed.

I claim:
 1. A valve device useable with a collection bag comprising:alower compartment defined by a gas and liquid impermeable bottom wallhaving at least one aperture arranged to fluidly communicate with acollection bag and a gas liquid impermeable first division plate; anodor-absorbing substrate positioned within said lower compartment; anupper compartment in fluid communication with said lower compartment andbeing defined on one side by a gas and liquid impermeable top wallhaving at least one aperture in communication with an externalenvironment of the valve device in use; and an expandable substratepositioned within said upper compartment, said substrate being arrangedwithin said upper compartment so that upon contact with moisture fromsaid first compartment, said substrate expands to close said aperturesin fluid communication with the external environment wherein gases fromthe collection bag are vented through the odor absorbing lowercompartment, through the upper compartment and exit through said atleast one aperture of the top wall but liquid is prevented from exitingthe valve device.
 2. A valve device according to claim 1 comprising asecond division plate and an intermediate compartment defined by saidfirst and second division plates and odor absorbing material positionedwithin said intermediate compartment, wherein said first division platecomprises an aperture such that said lower and intermediate compartmentsare in fluid communication and said second division plate comprises atleast one aperture such that said intermediate and upper compartmentsare in fluid communication.
 3. A valve device according to claim 1wherein the odor absorbing substrate is a pore-forming matrix includingadhesively attached active carbon and said gas and liquid impermeableupper and bottom walls are plastic.
 4. A valve device according to claim1 wherein said expandable substrate comprises at least plastic or sand.5. A valve device according to claim 1 wherein said expandable substrateis a dried sponge of synthetic material.
 6. A valve device according toclaim 1 wherein said expandable substrate is a superabsorbent material.7. A valve device according to claim 1 wherein said odor-absorbingsubstrate is a plastic impregnated with granulated active carbon.
 8. Avalve device in combination with a collection bag comprising a valvebody having a lower compartment defined by a gas and liquid impermeablebottom wall having at least one aperture arranged to fluidly communicatewith a collection bag and a gas liquid impermeable first division plate,an odor-absorbing substrate positioned within said lower compartment, anupper compartment in fluid communication with said lower compartment andbeing defined on one side by a gas and liquid impermeable top wallhaving at least one aperture in communication with an externalenvironment of the valve device in use, an expandable substratepositioned within said upper compartment, said substrate being arrangedwithin said upper compartment so that upon contact with moisture fromsaid first compartment, said substrate expands to close said aperturesin fluid communication with the external environment wherein gases fromthe collection bag are vented through the odor absorbing lowercompartment, through the upper compartment and exit through theapertures of the top wall but liquid is prevented from exiting theapertures of the top wall, and a collection bag for intake and storageof waste products, said bag having gas and liquid impermeable wallswherein said valve device sealingly mates with said collection bag.